And look back at Edgar's box top. You'll notice the relieved background is also textured! Combining both techniques deepens the shadows below the surface and creates a new look.
My plan is to create some texture tools from common home center items and show you how to make them yourself. No promises on when I'll get this done, but I think this should be easy to do with limited tools.
If you'd like to purchase a set of 12 texturing tools handmade by Edgar, you can reach out to him on Facebook (see below) Please tell him I sent you. 😀